In 1982, The black mayor of Los Angeles (Tom Bradley) was running for governor of California against his white Republican opponent. In the final weeks, the polls showed the race to be close, but every single one of them predicted a Bradley win with a fairly comfortable margin. On the day of the election, the exit polls all showed the election to a bit closer then predicted, but projected a Bradley win.

When the votes were counted, Bradley had narrowly lost the election. Post-election research revealed that some white voters had apparently lied about their support for Bradley, and the "undecideds" all broke for his opponent by an unusually huge margin. From this event over 25 years ago, the "Bradley Effect" was coined as a term in politics. It was also blamed for inaccurate polling in some later races, most notably Jesse Jackon's run for the nomination in 1988 against the frontrunner (Dukakis). Polls suggested he was going to be a serious contender for the nomination, win some states, and could count on getting at least a third of the votes nationally in the crowded field, but he actually received only a quarter.

In Barack Obama's fight for the nomination, some people suggested a Bradley Effect in New Hampshire, but other experts instead believed the polls were just seriously flawed. Some researchers also believed that a Bradley effect was present during Super Tuesday, which Obama had won but sometimes not by the margin predicted by the polls. It was generally close and there again was no consensus on this among political commentators.

The question is: Do you believe that the "Tom Bradley Effect" will influence the polls and exit polls during the general election? If so, how much of a margin do you think Obama would need before you'd call the race tied?